Breast pump



FIG. 1 is a top perspective view of a breast pump showing the claimed design;

FIG. 2 is a bottom perspective view thereof;

FIG. 3 is a front view thereof;

FIG. 4 is a back view thereof;

FIG. 5 is a right side view thereof;

FIG. 6 is a left side view thereof;

FIG. 7 is a top view thereof; and,

FIG. 8 is a bottom view thereof.

The broken lines shown in the figures depict portions of the breast pump that form no part of the claimed design. 

CLAIM The ornamental design for a breast pump, as shown and described. 